SONOFF Zigbee Thermostatic Radiator Valve (TRVZB) Review

The SONOFF Zigbee Thermostatic Radiator Valve (TRVZB) is designed to replace standard manual or thermostatic radiator heads, providing app-based control and scheduling. Working on the Zigbee 3.0 protocol, it requires a compatible hub (like the SONOFF Zigbee Bridge Pro) to function. Its primary goal is to provide room-by-room temperature management, ensuring that energy isn't wasted heating bedrooms during the day or living areas late at night. The unit features a simple LED display for local adjustments and a sleek, modern design that fits most UK radiator valves with the included adapters.

In a typical UK semi-detached setting, the TRVZB performs well for basic automation. The response time to app commands is generally quick thanks to Zigbee's efficiency. However, users may find the internal temperature sensor slightly affected by its proximity to the hot radiator—a common issue with all TRVs—which may require a temperature offset adjustment in the app. The noise level during valve adjustment is audible but not disruptive, making it suitable for bedrooms for most users, though light sleepers should take note.

Realistic savings with smart TRVs in the UK typically range between 5% and 12% on annual heating bills, primarily by preventing 'over-heating' of unused rooms. For a home with a £1,200 annual gas bill, this could represent a saving of £60–£144 per year. However, these savings only materialise if the rest of the heating system is balanced and the boiler isn't constantly cycling for a single small radiator. Users should be cautious of 'instant payback' claims, as the initial cost of the units and the required Zigbee hub must be recouped first.

Installation is a simple 'screw-off, screw-on' process for most UK radiators with M30 x 1.5mm threads. The package includes several adapters for different valve types, though you should check your existing valve compatibility before purchase. No plumbing or draining of the system is required.

The unit runs on AA batteries (usually 3x). Depending on the frequency of adjustments, expect to replace these every 6 to 12 months. Using high-quality alkaline batteries is recommended to prevent leakage and ensure reliable valve operation during winter.